Determination of the relative combining ability of corn (Zea mays L.) inbred lines is an important feature of applied corn breeding program. Combining ability is measured by the relative performance of a line in testcrosses to one or more tester. CIMMYT inbred lines with white endosperm used as tester. The inbred lines were derived from different Tainan-White(TNW) populations, evaluated at S4 generation. The results indicated significant differences existed respectively in the general and specific combining ability of agronomic characters among TNW inbred lines in intra-population or inter-populations.